1. Field of the Invention
The present invention relates to a sewing machine having a height reduced as much as possible. The present invention can be applied to a small domestic sewing machine.
2. Discussion of the Related Art
It has been required to reduce the size of sewing machines, especially of domestic sewing machines. An example of the small-sized sewing machines is disclosed in Japanese Examined Patent Publication (KOKOKU) No. 30179/1969. The sewing machine comprises a bed housing, an arm housing rising from one end of the bed housing and extending to the other end of the bed housing over the bed housing, a link mechanism built-in in the arm housing, a vertically extending longitudinally-long needle bar held at the end of the link mechanism and having a needle, and a drive unit for actuating the link mechanism. The drive unit includes a drive motor and a main shaft disposed between the drive motor and the link mechanism.
The drive unit is actuated after the upper thread is run through the needle. The link mechanism swings, and the longitudinally-long needle bar reciprocates in the vertical direction. Thus, the needle held at the end of the needle bar penetrates a cloth, and stitches are formed.
As described above, the needle bar having the needle at the end has a longitudinally-long shape, and reciprocates in the vertical direction. Considering the reciprocating movement of the needle bar in the vertical direction, even if the size of the arm housing may be reduced, the top end of the needle bar goes through a hole of the arm housing and inevitably protrudes from the top surface of the arm housing, since it reciprocates in the vertical direction. Thus, there has been a limitation on the reduction of the sewing machine height. In addition, though the sewing machine disclosed in Japanese Examined Patent Publication (KOKOKU) No. 30179/1969 has a drive motor disposed in the bed housing, the main shaft is so vertically disposed that it penetrates the boundary between the bed housing and the arm housing and protrudes by half of its length. Thus, there has been another limitation on the reduction of the sewing machine height.